U.S. patent application number 12/992163 was filed with the patent office on 2011-03-31 for composite liftgate system.
Invention is credited to Norman Guschewski, Alexander Kiselev, Christopher John Kuntze, Martin Mcleod, Stephen R. Roddy, Gari M. Schalte, Michelle Vanbuskirk.
Application Number | 20110074179 12/992163 |
Document ID | / |
Family ID | 41376522 |
Filed Date | 2011-03-31 |
United States Patent
Application |
20110074179 |
Kind Code |
A1 |
Kuntze; Christopher John ;
et al. |
March 31, 2011 |
Composite Liftgate System
Abstract
The present invention is a thermoplastic composite liftgate
system with reinforcements in key areas to allow the system to meet
performance requirements, while lowering the tooling investment,
lowering the system mass, and improving the styling flexibility.
The present invention includes an inner panel and at least one
bracket or reinforcement member connected to the inner panel such
that when a force is applied to the bracket, the force is
distributed to the inner panel.
Inventors: |
Kuntze; Christopher John;
(Clarkston, MI) ; Roddy; Stephen R.; (Harrison
Township, MI) ; Mcleod; Martin; (Barrie, CA) ;
Vanbuskirk; Michelle; (Rochester Hills, MI) ;
Kiselev; Alexander; (Rochester Hills, MI) ; Schalte;
Gari M.; (Oakland Twp, MI) ; Guschewski; Norman;
(Rochester, MI) |
Family ID: |
41376522 |
Appl. No.: |
12/992163 |
Filed: |
June 1, 2009 |
PCT Filed: |
June 1, 2009 |
PCT NO: |
PCT/CA09/00747 |
371 Date: |
November 11, 2010 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61130489 |
May 30, 2008 |
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Current U.S.
Class: |
296/146.6 ;
296/146.8 |
Current CPC
Class: |
B60J 5/107 20130101 |
Class at
Publication: |
296/146.6 ;
296/146.8 |
International
Class: |
B60J 5/10 20060101
B60J005/10; B62D 29/04 20060101 B62D029/04; B62D 33/027 20060101
B62D033/027 |
Claims
1. A composite liftgate system, comprising: an inner panel; and a
bracket connected to said inner panel such that when a force is
applied to said bracket, the force is distributed to said inner
panel.
2. The composite lift gate system of claim 1, further comprising:
at least one lower pillar reinforcement connected to said inner
panel for increasing the structural integrity of said inner panel;
at least one upper pillar reinforcement connected to said inner
panel for increasing the structural integrity of said inner panel;
and at least one tether for connecting said at least one lower
pillar reinforcement to said at least one upper pillar
reinforcement, and for connecting said at least one lower pillar
reinforcement to said bracket, and when said inner panel becomes
cracked or deformed, said at least one tether will maintain a
connection between said at least one lower pillar reinforcement and
said at least one upper pillar reinforcement, and maintain a
connection between said at least one lower pillar reinforcement and
said bracket.
3. The composite lift gate system of claim 2, said at least one
tether being one selected from the group consisting of braded
stainless steel cable, stainless steel tubing, a rolled or stamped
steel channel, and a wide webbing material.
4. The composite lift gate system of claim 2, further comprising an
outer panel operable for being connected to said inner panel,
wherein said lower pillar reinforcement, said upper pillar
reinforcement, and said at least one tether are disposed between
said inner panel and said outer panel when said inner panel is
connected to said outer panel.
5. The composite lift gate system of claim 2, further comprising:
at least one latch channel extending from the center of said
bracket to said at least one lower pillar reinforcement; at least
one channel extending along said inner panel and substantially
perpendicular to said at least one latch channel; and at least one
side channel extending along an outer portion of said inner panel,
said at least one side channel being intersected by said at least
one latch channel.
6. The composite lift gate system of claim 4, further comprising a
plurality of secondary reinforcement members, a portion of said
plurality of secondary reinforcement members disposed in at least
one latch channel, a portion of said plurality of secondary
reinforcement members disposed in said channel, and a portion of
said plurality of secondary reinforcement members disposed in said
at least one side channel.
7. The composite lift gate system of claim 4, wherein said at least
one latch channel is substantially 70 millimeters wide and
substantially 70 millimeters deep.
8. The composite lift gate system of claim 4, wherein said at least
one channel is substantially 70 millimeters wide and substantially
70 millimeters deep.
9. The composite lift gate system of claim 4, wherein said at least
one side channel is substantially 70 millimeters wide and
substantially 70 millimeters deep.
10. The composite lift gate system of claim 4, said plurality of
secondary reinforcement members further comprising a plurality of
ribs.
11. The composite lift gate system of claim 1, said bracket
connected to said inner panel further comprising a wide reinforcing
bracket being operable for spreading said force applied to said
wide reinforcing bracket to said inner panel.
12. The composite lift gate system of claim 1, wherein said bracket
is connected to said inner panel through the use of a structural
adhesive.
13. The composite lift gate system of claim 1, wherein said bracket
is connected to said inner panel through the use of insert
molding.
14. A composite liftgate system, comprising: an inner panel; an
outer panel operable for being connected to said inner panel such
that a cavity is formed between said outer panel and said inner
panel; a plurality of reinforcements connected to said inner panel
for increasing the structural integrity of said inner panel; and a
bracket connected to said inner panel in a location such that said
bracket is positioned between said inner panel and said outer
panel, and when a force is applied to said bracket, the force is
distributed to said inner panel.
15. The composite liftgate system of claim 14, said bracket further
comprising a wide reinforcing bracket.
16. The composite lift gate system of claim 15, wherein said wide
reinforcing bracket is connected to said inner panel through the
use of a structural adhesive.
17. The composite lift gate system of claim 15, wherein said wide
reinforcing bracket is connected to said inner panel through the
use of insert molding.
18. The composite liftgate system of claim 14, said plurality of
reinforcements further comprising: at least one lower pillar
reinforcement operable for connection with said inner panel and
being located in said cavity for increasing the rigidity of said
inner panel; at least one upper pillar reinforcement operable for
connection with said inner panel and being located in said cavity
for increasing the rigidity of said inner panel; and more than one
tether, one of said more than one tether connected to both of said
at least one lower pillar reinforcement and said at least one upper
pillar reinforcement, one of said more than one tether connected to
both of said at least one lower pillar reinforcement and said
bracket, said more than one tether being operable to maintain a
connection between said at least one lower pillar reinforcement and
said at least one upper pillar reinforcement and between said at
least one upper pillar reinforcement and said bracket when said
inner panel becomes cracked or deformed.
19. The composite lift gate system of claim 18, wherein said more
than one tether is one selected from the group consisting of braded
stainless steel cable, stainless steel tubing, a rolled or stamped
steel channel, and a wide webbing material.
20. The composite lift gate system of claim 18, wherein each of
said at least one lower pillar reinforcement and said at least one
upper pillar reinforcement are connected to said inner panel
through the use of a structural adhesive.
21. The composite lift gate system of claim 18, wherein each of
said at least one lower pillar reinforcement and said at least one
upper pillar reinforcement are connected to said inner panel
through the use of insert molding.
22. The composite lift gate system of claim 18, wherein at least
one latch channel extending from the center of said bracket to said
at least one lower pillar reinforcement; at least one channel
extending along said inner panel and substantially perpendicular to
said at least one latch channel; at least one side channel
extending along an outer portion of said inner panel, said at least
one side channel being intersected by said at least one latch
channel; and a plurality of ribs being operable for providing
support for each of said at least one latch channel, said at least
one channel, and said at least one side channel, wherein at least
one of said plurality of ribs is formed as part of said at least
one latch channel, at least one of said plurality of ribs being is
formed as part of said at least one channel, and at least one of
said plurality of ribs is formed as part of said at least one side
channel.
23. The composite lift gate system of claim 22, further comprising
said at least one latch channel to be substantially 70 millimeters
wide and substantially 70 millimeters deep.
24. The composite lift gate system of claim 22, further comprising
said at least one channel to be substantially 70 millimeters wide
and substantially 70 millimeters deep.
25. The composite lift gate system of claim 22, further comprising
said at least one side channel to be substantially 70 millimeters
wide and substantially 70 millimeters deep.
26. A composite liftgate system, comprising: an inner panel; an
outer panel operable for being connected to said inner panel such
that a cavity is formed between said inner panel and said outer
panel; at least one lower pillar reinforcement connected to said
inner panel and disposed in said cavity, wherein said at least one
lower pillar reinforcement increases the structural integrity of
said inner panel; at least one upper pillar reinforcement connected
to said inner panel and disposed in said cavity, wherein said at
least one upper pillar reinforcement increases the structural
integrity of said inner panel; a plurality of tethers, one of said
plurality of tethers connected to said at least one lower pillar
reinforcement and to said at least one upper pillar reinforcement
such that said at least one tether will remain connected to said at
least one lower pillar reinforcement and said at least one upper
pillar reinforcement when said inner panel becomes cracked or
deformed; and a wide reinforcing bracket connected to said inner
panel such that said wide reinforcing bracket is disposed in said
cavity, and when a force is applied to said wide reinforcing
bracket, said force is distributed to said inner panel; wherein one
of said plurality of tethers is connected to said at least one
lower pillar reinforcement and said wide reinforcing bracket such
that said at least one tether will remain connected to said at
least one lower pillar reinforcement and said wide reinforcing
bracket when said inner panel becomes cracked or deformed.
27. The composite lift gate system of claim 26, wherein said
plurality of tethers are constructed of one selected from the group
consisting of braded stainless steel cable, stainless steel tubing,
a rolled or stamped steel channel, and a wide webbing material.
28. The composite lift gate system of claim 26, further comprising:
at least one latch channel formed as part of said inner panel, said
at least one latch channel extending from the center of said
bracket to said at least one lower pillar reinforcement; at least
one channel formed as part of said inner panel, said at least one
channel extending along said inner panel and substantially
perpendicular to said at least one latch channel; at least one side
channel formed as part of said inner panel, said at least one side
channel extending along an outer portion of said inner panel, said
at least one side channel being intersected by said at least one
latch channel; and a plurality of ribs formed as part of said inner
panel, said plurality of ribs being operable for providing support
for each of said at least one latch channel, said at least one
channel, and said at least one side channel, wherein at least one
of said plurality of ribs is formed as part of said at least one
latch channel, at least one of said plurality of ribs being is
formed as part of said at least one channel, and at least one of
said plurality of ribs is formed as part of said at least one side
channel.
29. The composite lift gate system of claim 28, wherein said at
least one latch channel is substantially 70 millimeters wide and
substantially 70 millimeters deep.
30. The composite lift gate system of claim 28, wherein said at
least one channel is substantially 70 millimeters wide and
substantially 70 millimeters deep.
31. The composite lift gate system of claim 28, wherein said at
least one side channel is substantially 70 millimeters wide and
substantially 70 millimeters deep.
32. The composite lift gate system of claim 26, wherein each of
said wide reinforcing bracket, said at least one lower pillar
reinforcement, and said at least one upper pillar reinforcement are
connected to said inner panel through the use of a structural
adhesive.
33. The composite lift gate system of claim 26, wherein each of
said wide reinforcing bracket, said at least one lower pillar
reinforcement, and said at least one upper pillar reinforcement are
connected to said inner panel through the use of insert molding.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. Provisional
Application No. 61/130,489, filed May 30, 2008. The disclosure of
the above application is incorporated herein by reference.
FIELD OF THE INVENTION
[0002] The present invention relates to liftgates for automobiles.
More specifically, the present invention relates to a composite
liftgate for an automobile.
BACKGROUND OF THE INVENTION
[0003] One of the current trends in the automobile industry is to
lower vehicle weight to help achieve better fuel economy, thus
helping to meet fuel economy standards and to offset the higher
fuel prices. Another trend is that there is a broader range of
vehicle models, which in turn reduces the volume of vehicles
produced on a per model basis. Liftgates are traditionally made
from stamped steel panels that are heavy and have a high tooling
cost. Sheet Molding Compound (SMC) is an alternative to steel for
the inner and outer panels of the liftgate. Using SMC has several
manufacturing concerns related to the material and process. Steel
and SMC liftgates have a mass penalty over thermoplastics. There
are also styling restrictions with traditional sheet metal
components. Thermoplastic composite type materials used for
liftgate applications also have difficulty meeting customer
performance specifications.
[0004] Another concern with the manufacture of liftgates is that
typical lifgates are manufactured as a relatively flat or smoothly
contoured panel, with structural reinforcements such as ribs being
added onto the panel. This will also add weight and increase
manufacturing complexity as well.
[0005] One solution to this problem has been the 2008 Nissan Murano
composite liftgate system, which has helped to satisfy the weight
savings and the tooling cost concerns, but utilizes a typical bolt
in small steel reinforcement at the latch which secures one end of
the liftgate to the vehicle. This does not meet the higher load
requirements desired in some applications, such as the latch pull
test.
[0006] Accordingly, there exists a need for a composite liftgate
which is both lightweight, as well as structurally sound enough to
meet various load requirements.
SUMMARY OF THE INVENTION
[0007] The present invention is a thermoplastic composite liftgate
system with reinforcements in key areas to allow the system to meet
performance requirements, while lowering the tooling investment,
lowering the system mass, and improving the styling flexibility.
The present ivention includes an inner panel, and at least one
bracket, or reinforcement, connected to the inner panel such that
when a force is applied to the bracket, the force is distributed to
the inner panel.
[0008] Further areas of applicability of the present invention will
become apparent from the detailed description provided hereinafter.
It should be understood that the detailed description and specific
examples, while indicating the preferred embodiment of the
invention, are intended for purposes of illustration only and are
not intended to limit the scope of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] The present invention will become more fully understood from
the detailed description and the accompanying drawings,
wherein:
[0010] FIG. 1 is a rear view of an inner panel having multiple
reinforcements used in a liftgate system, according to the present
invention;
[0011] FIG. 2 is an enlarged perspective view of a lower pillar
reinforcement used for a composite liftgate system, according to
the present invention;
[0012] FIG. 3 is an enlarged perspective view of an upper pillar
reinforcement used for a composite liftgate system, according to
the present invention;
[0013] FIG. 4 is an enlarged perspective view of a wide reinforcing
bracket used for a composite liftgate system, according to the
present invention;
[0014] FIG. 5 is a perspective view of an inner panel used for a
composite liftgate system, according to the present invention;
[0015] FIG. 6 is a rear view of an inner panel used for a composite
liftgate system, according to the present invention;
[0016] FIG. 7 is a front view of an inner panel used for a
composite liftgate system, according to the present invention;
[0017] FIG. 8 is a side view of an inner panel used for a composite
liftgate system, according to the present invention;
[0018] FIG. 9 is an exploded perspective view of a first embodiment
of an outer panel used in a composite liftgate system, according to
the present invention; and
[0019] FIG. 10 is a perspective view of a second embodiment of an
outer panel used in a composite liftgate system, according to a
first embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0020] The following description of the preferred embodiment(s) is
merely exemplary in nature and is in no way intended to limit the
invention, its application, or uses.
[0021] The composite liftgate system of the present invention
utilizes a wide reinforcing bracket along with a latch which aids
in spreading the load applied to the bracket over a larger area.
The wide reinforcement bracket adds more structure by attaching to
the inner panel with structural adhesive or insert molding.
Additionally, the wide reinforcing bracket is also tied into other
reinforcing brackets with steel tethers. The other reinforcing
brackets are also connected to a hinge system through the use of
additional steel tethers. The steel tethers are in the form of
cables, stampings, tubes, etc., which reinforce the composite gate
and the latch system (which ties to the body) to a counter balance
system and the hinge system (which also ties back into the body
structure).
[0022] The composite liftgate of the present invention provides the
advantage over other inventions through the use of a wide steel
reinforcement in the area of the latch. The wide steel
reinforcement is installed with structural adhesive, or in another
embodiment is insert molded for added structure. Mechanical
fasteners are used as a temporary connection to hold the wide steel
reinforcement in place until the structural adhesive sets up and
cures. Tethers, similar to the tethers mentioned above, tie the
lower reinforcement in the latch area to other important reinforced
areas that extend to other reinforcements and to the upper hinges
that again tie into the metallic body structure.
[0023] Another feature of the present invention is that the
liftgate includes an inner composite panel. The structure of the
inner composite panel includes various shapes and ribs which
transfer the load path up through key structural areas of the
assembly.
[0024] The inner panel is connected to an outer panel to form the
composite liftgate of the present invention. The inner panel and
outer panel are bonded together through the use of a urethane
bonding. The inner panel provides structural support for the
composite liftgate of the present invention not only through the
shape of the inner panel as described above, but the material used
to make the inner panel provides structural support as well. The
inner panel is made of a structural thermoplastic, such as a
polypropylene, a thermoset or thermoplastic such as a reinforced
polypropylene (RPP), and is preferably a 40% glass-filled
polypropylene. The outer panel is made of a typical thermoplastic
used as a show surface, such as a thermoplastic polyolefin (TPO),
and provides no significant structural support for the composite
liftgate of the present invention.
[0025] An embodiment of a composite liftgate system is shown in the
Figures generally at 10. The liftgate 10 includes a bracket 12,
which is connected to an inner panel 14. In this embodiment, the
bracket 12 is structurally bonded using an adhesive 16, but it is
within the scope of the invention that the bracket 12 could be
insert molded to connect the bracket 12 to the inner panel 14.
[0026] Also connected to the inner panel 14 are a set of lower
pillar reinforcements 18 and a set of upper pillar reinforcements
20; both the reinforcements 18,20 are connected to the inner panel
14 in a similar manner as the bracket 12. Each of the lower pillar
reinforcements 18 are typically connected to a gas strut (not
shown), and the upper pillar reinforcements are typically attached
to a hinge system (not shown), with the hinge system and gas strut
connected to a vehicle.
[0027] The liftgate 10 of the present invention also includes a
series of reinforcement members 22. The reinforcement members 22
will keep the liftgate 10 together even if the inner panel 14
becomes cracked or deformed from being subjected to an impact. In
this embodiment, the reinforcement members 22 are in the form of
tethers 22. The tethers 22 may be braded stainless steel cable,
stainless steel tubing, a rolled or stamped steel channel, or a
wide webbing material, similar to what is used in common seat
belts.
[0028] Formed as part of the inner panel 14 are a first pair of
channels or latch channels 24. The channels 24 run in a
substantially diagonal pattern from the near the center of the
bracket 12 to the lower pillar reinforcements 18. In this
embodiment, the channels are 70 mm wide and 70 mm deep, but it is
within the scope of the invention that other dimensions may be used
as well. The two channels 24 shown in the Figures produce
substantially a "V-pattern."
[0029] There are also two second channels 26 which are
substantially perpendicular to the latch channels 24. Again, the
additional channels 26 are 70 mm wide and 70 mm deep, but it is
within the scope of the invention that other dimensions be used as
well.
[0030] The inner panel 14 also includes a pair of third channels,
or side channels 28, which again are 70 mm wide and 70 mm deep, and
provide further structural support for the inner panel 14. The side
channels 28 extend along each side of the inner panel 14, and
intersect the latch channels 24 respectively in the general area of
the lower pillar reinforcements 18.
[0031] To further improve the structural integrity of the inner
panel 14, there is also a plurality of secondary reinforcement
members, or ribs 30. The ribs 30 are also formed as part of the
inner panel 14, similar to the channels 24,26,28. The ribs 30 are
incorporated into all of the channels 24,26,28, and improve the
rigidity of the entire lift gate 10.
[0032] The liftgate 10 also includes an outer panel, generally
shown at 32 in FIGS. 9 and 10. The outer panel 32 is connected to
the inner panel 14 such that a cavity is formed between the inner
panel 14 and outer panel 32. The outer panel 32 may be formed of
two separate pieces, as shown in FIG. 9, or may be formed as a
single piece, as shown in FIG. 10.
[0033] The description of the invention is merely exemplary in
nature and, thus, variations that do not depart from the gist of
the invention are intended to be within the scope of the invention.
Such variations are not to be regarded as a departure from the
spirit and scope of the invention.
* * * * *